Fire up the PC and software, hook it up to your 3GX unit.
Go to this page:
click the "Revert Update" button at the bottom right corner. Follow the instructions, you'll be shown various software revisions to choose from, select V3.1. You'll update the software.
Yes, you need to run through the DIR setup, rudder setup, and throttle/pitch calibration steps, but this takes less than 5 minutes. Remember, your radio will already be set up to get the collective and cyclic pitch ranges, you won't need to dig out the pitch gauge and repeat all that.
Center the tail rotor pitch slider at neutral and don't forget to run the tail gyro setup stuff.
* Making the World Better -- One Helicopter at a time! *